Question

A capacitor of capacitance $50\text{pF}$ is charged by $100\text{V}$ source. It is then connected to another uncharged identical capacitor. Electrostatic energy loss in the process is $x\text{nJ}$. Find the value of $x$.

• A. 12.50
• B. 125
• C. 125.00
• D. 125.0

Answer 1

Answer: (A), (B), (C), (D)

Electrical energy lost $=\frac{1}{2}\left(\frac{1}{2}C{V}^2\right)$
$=\frac{1}{2}\times \frac{1}{2}\times 50\times {10}^{-12}\times (100{)}^2$
$=\frac{500}{4}nJ$
$=125nJ$